Add support for Rector 2.x

Author: fooman

Diff for: composer.json

@@ -13,7 +13,7 @@
         "ext-simplexml": "*",
         "ext-dom": "*",
         "squizlabs/php_codesniffer": "^3.6.1",
-        "rector/rector": "^1.2.4",
+        "rector/rector": "^1.2.4 || ^2.0.0",
         "phpcsstandards/phpcsutils": "^1.0.5",
         "magento/php-compatibility-fork": "^0.1"
     },